Safety shuffle: 49ers sign Bethea to replace Whitner

Well, it didn’t take long for the 49ers to find a replacement for departed safety Donte Whitner.

Shortly after free agency began at 1 p.m. today, the 49ers signed Colts safety Antoine Bethea, a league source confirmed. Bethea signed a four-year deal worth just over $25 million, according to a league source.

Bethea will replace Whitner, a Cleveland native who signed a four-year deal reportedly worth $28 million with the Browns today. Whitner earned just under $4 million in his three seasons with the 49ers.

Bethea, who will turn 30 in July, is a two-time Pro Bowler (2007, ’09) who has started 96 straight games dating to 2008. A sixth-round pick of the Colts in 2006, Bethea had 110 tackles, two interceptions and six pass breakups last year. He has collected four straight 100-tackle seasons.

Bethea, who is a year older than Whitner, could provide a steadying presence for what could be an exceedingly young and inexperienced secondary. If free-agent cornerback Tarell Brown signs elsewhere, the other starters could be safety Eric Reid, 22, and cornerbacks Tramaine Brock, 25, and Chris Culliver, 25. Bethea has 123 career starts, 100 more than Reid, Brock and Culliver have combined.